1. Field Of The Invention
This invention relates to the operation of flush valves and, more particularly, to non-contact, sensor operated mechanisms for operating flush valves.
2. Description Of The Prior Art
The use of flush valves for controlling the flow of water to plumbing fixtures, particularly in public facilities, is well known. Such flush valves typically include a movable diaphragm which closes the water supply and is tripped by a handle operated trip mechanism. See, for example, U.S. Pat. Nos. 1,756,263, 1,858,470, 4,202,525 and 4,327,891. Push button arrangements for tripping diaphragm flush valves have also been developed. U.S. Pat. No. 3,695,288 and 3,778,023. All of these arrangements provide controlled, on demand flushing of the plumbing fixture through controlling the flush valve trip mechanism.
It has long been recognized that human contact with the handle, push button, or other device for tripping the flush valve is not particularly sanitary, especially in heavily used public restroom facilities. It has also been recognized that non-contact arrangements for tripping the flush valve are desirable. For example, U.S. Pat. No. 3,731,025 discloses an arrangement in which a breath operated disc connected to a switch arm is used to activate an electric solenoid or motor which moves an actuator rod to contact the flush valve trip mechanism. Although this arrangement provides a sanitary, non-contact method of operating the flush valve, the mechanism is quite delicate and the use of a person's breath to operate the switch is not generally acceptable to the public. The most common, non-contact method of activating a flush valve or the like is the use of a sensor operated system. See, for example, U.S. Pat. Nos. 2,438,207, 2,603,794, 3,339,212, 3,434,164, 3,462,769, 3,670,167, 3,863,196, 4,309,781, 4,624,017, 1,667,350, 4,707,867, 4,742,583, 4,793,588 and 4,805,247. These systems provide for automatic tripping of the flush valve by first detecting when a person is present at the plumbing fixture, then detecting when the person leaves the fixture, and then triggering the flush mechanism for the fixture. While these systems provide for a non-contact and sanitary flushing of the plumbing fixture, it does so at the expense of the user's direct control of the flush mechanism which is present in the handle and push button operated systems.
Accordingly, it is an object of the present invention to provide a system for controlling the operation of a flush valve which combines the non-contact, sanitary features of a sensor operated system in an on demand, user controlled flushing arrangement. It is a further object of the present invention to provide such an arrangement in a simple and inexpensive system which is reliable in operation.